Drum-mill.



No. 813,076. PATENTED FEB. 20, 1906. vR. BENEKE.

DRUM MILL.

APPLIGATIQN FILED JAN. 1e, 1905.

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M m Q M in the accomp an v BICI-IARD BENEKE, BROMBERG, GERMANY.

DRUM-NULL.

Speccaton of Letters Patent.

Patented Feb. 20, 1906.

Application filed January 18, 1905. Serial No. 241,607.

To all whom it 17m/y concern:

Be it known that I, RICHARD BENEKE, director, a subject of the King of Prussia, German Emperor, residing at No. 6 Bahnhofstrasse, Bromberg, German Empire, have invented new and4 useful Improvements in Drum-Mills, of which the following is a specilication.

My invention relates to an improved boss for drum-mills, the purpose of which is to admit of material not passing through the sieve being returned to the grinding-drum and at the same time to allow of new material being fed to the drum.

One embodiment of the invention is shown 'ng drawings, in which- Figure 1 is an inside view of the apparatus; Fig. 2 a section on the line A B of Fig. 1, and Fig. 3 a section on the line C D of Fig. 1.

The material falling out of the grindingdrum g through the apertures h descends upon the two perforated shells or sieves t and 7c in the ordinary manner. The coarse material remains lying on the sieve le and passes into the casing a, as shown at s. Here the blades b scoop it up and return it through the boss into the interior of the grinding-drum In order to admit this coarse mateby the shortest path the rim fm. of the again. rial to travel unimpeded into the grindingdrum, boss, which is open laterally, is provided with apertures n, corresponding in number with the number of blades l), and through these apertures the material lying on each blade passes unobstructed. The material falls upon that one of a series of wings or vanes o which lies opposite the aperture n which is uppermost for the time being. These vanes 0 have a spiral curve and may be regarded as extensions of the blades b. Since the boss, as Fig. 3 shows, is open at the side toward the interior of the grinding-drum and since the vanes o travel against the direction of fall of the material s, the latter immediately a blade b discharges its contents slides through the boss and falls unimpeded by the shortest path from the vane o. In this manner the material is returned to the grinding-drum in a continuous stream, no shocks being occasioned.

In order to enable fresh material to be fed through the boss into the grinding-drum, the

partition on the outer side of the drum presents inlets u 'u u, Fig. 1, and a hopper v is secured to the boss at this side. The charge falling through the hopper passes through the apertures u into the interior of the drum g. To prevent the fresh charge entering the inlets n of the boss-rim, scoop-shaped partitions :z: may be located between the vanes o, which partitions, owing to their inclined position in rotating, convey the charge of fresh material from the hopper 'u into the grindingdrum. Thus it will be seen that the boss comprises two sets of channels-one set communicating with the tailings-return ribs b and the other with the hopper discharge-opening.

Instead of partitions Qc it is obvious that any other suitable means may be employed to prevent the fresh charge entering the apertures in the rim m of the boss. Thus, for example, covers might be used, fitted so as not lto obstruct the free eXit of the coarse material.

Having thus described I claim is 1. In a drum-mill having a casing at the drum end, communicating with the outer shell of the drum, and presenting blades running from the periphery toward the center; in combination, a central boss for the drumshaft, having a perforated rim, communicating peripherally with the casing and laterally with the grinding drum; spirally curved vanes in the interior of the boss, rotating against the direction of fall of material through the perforated rim, located one below each aperture in the latter; a perforated partition dividing the hopper from the boss and means for preventing the hopper charge from passing through the perforated bossrim, substantially as described.

2. In a drum-mill having a casing at the drum end, communicating with the outer shell of the drum, and presenting blades running from the periphery toward the center in combination, a central boss for the drumshaft, having a perforated rim, communicating peripherally with the casing and laterally with the grinding drum; spirally curved vanes in the interior of the boss, rotating my invention, what IOO against the direction of fall of material through the perforated rim, located one be- In Witness whereof I have hereunto signed loW each aperture in the latter g a perforated my name, this 21st day of December,-1904, partition dividing the hopper from the boss 3 in the presence of tWo subscribing Witnesses.

and scoop-shaped members located between RICHARD BENEKE. 5 the said Vanes, for preventing the hopper Witnesses:

charge from passing through the perforated WOLDEMAR HAUPT,

boss-rim, substantially as described. HENRY HAsPER. 

